Method of manufacturing semiconductor packaging

Abstract

The present disclosure is related to a method of providing a die structure for semiconductor packaging. The method includes providing a substrate with a bonding pad; forming a patterned mask layer on the substrate; forming an opening on the mask layer; depositing a conductive layer in the opening; forming a cap layer on the conductive layer, and removing the mask layer. The cap layer forming step allows the contacting area between the cap layer and the conductive layer to be substantially equal to the top surface area of the conductive layer by reflowing solder material prior to the removal of the mask layer.

What is claimed is: 
     
       1. A method of providing a semiconductor structure, the method comprising the steps of:
 providing a substrate with at least a bonding pad on the substrate; 
 forming a patterned mask layer on the substrate, wherein the patterned mask layer includes an opening which exposes at least a part of the bonding pad; 
 depositing a conductive layer in the opening, wherein a height difference exists between a top surface of the conductive layer and a top surface of the adjacent mask layer, and the top surface of the conductive layer is lower than the top surface of the adjacent mask layer; and wherein a ratio of the height difference and a thickness of the mask layer is controlled to be in a range of from ¼ to ½; 
 forming a cap layer on the conductive layer, wherein the cap layer is a solder layer, wherein forming the cap layer comprises a reflowing step; and 
 removing the patterned mask layer; 
 wherein the cap layer forming step allows a contacting area between the cap layer and the conductive layer to be substantially equal to the top surface area of the conductive layer; 
 wherein forming the cap layer comprises a disposing step which is random spraying, and the reflowing step is subsequent to the disposing step; 
 wherein the random spraying comprises positioning a plurality of solder balls on the conductive layer. 
 
     
     
       2. The method as in  claim 1 , further comprising a step of forming an under bump metallization (UBM) layer. 
     
     
       3. The method as in  claim 2 , wherein the UBM layer is formed by sputtering, vapor deposition, or printing. 
     
     
       4. The method as in  claim 2 , further comprising a step of removing the UBM layer. 
     
     
       5. The method as in  claim 1 , wherein the height difference is in a range of from ¼ to ⅓ of the thickness of the mask layer. 
     
     
       6. The method as in  claim 1 , wherein the conductive layer is formed by materials selected from the group of nickel, copper, gold, and the combination thereof. 
     
     
       7. A method of providing a semiconductor structure, the method comprising the steps of:
 providing a substrate with at least a bonding pad on the substrate; 
 forming a patterned mask layer on the substrate, wherein the patterned mask layer includes an opening which exposes at least a part of the bonding pad; 
 depositing a conductive layer in the opening, wherein a height difference exists between a top surface of the conductive layer and a top surface of the adjacent mask layer, and the top surface of the conductive layer is lower than the top surface of the adjacent mask layer; 
 forming a cap layer on the conductive layer, wherein the cap layer is a solder layer, wherein forming the cap layer comprises a reflowing step; and 
 removing the patterned mask layer; 
 wherein the cap layer forming step allows a contacting area between the cap layer and the conductive layer to be substantially equal to the top surface area of the conductive layer; 
 wherein forming the cap layer comprises a disposing step which can be ball dropping, random spraying, solder paste spreading, or the combination thereof; 
 wherein the removing step can be achieved concomitantly with the reflowing step under an elevated temperature treatment. 
 
     
     
       8. The method as in  claim 7 , further comprising a step of forming an under bump metallization (UBM) layer. 
     
     
       9. The method as in  claim 8 , wherein the UBM layer is formed by sputtering, vapor deposition, or printing. 
     
     
       10. The method as in  claim 8 , further comprising a step of removing the UBM layer. 
     
     
       11. The method as in  claim 7 , wherein the height difference is in a range of from about ¼ to about ⅓ of the thickness of the mask layer. 
     
     
       12. The method as in  claim 7 , wherein the conductive layer is formed by materials selected from the group of nickel, copper, gold, and the combination thereof. 
     
     
       13. The method as in  claim 7 , wherein the reflowing step is subsequent to the disposing step. 
     
     
       14. A method of providing a semiconductor structure, the method comprising the steps of:
 providing a substrate with at least a bonding pad on the substrate; 
 forming a patterned mask layer on the substrate, wherein the patterned mask layer includes an opening which exposes at least a part of the bonding pad; 
 depositing a conductive layer in the opening, wherein a height difference exists between a top surface of the conductive layer and a top surface of the adjacent mask layer, and the top surface of the conductive layer is lower than the top surface of the adjacent mask layer; 
 forming a cap layer on the conductive layer; and 
 removing the patterned mask layer; 
 wherein the cap layer forming step allows a contacting area between the cap layer and the conductive layer to be substantially equal to the top surface area of the conductive layer; 
 wherein forming the cap layer comprises a disposing step which is random spraying, and a reflowing step is subsequent to the disposing step; 
 wherein the random spraying comprises positioning a plurality of solder balls on the conductive layer. 
 
     
     
       15. A method of providing a semiconductor structure, the method comprising the steps of:
 providing a substrate with at least a bonding pad on the substrate; 
 forming a patterned mask layer on the substrate, wherein the patterned mask layer includes an opening which exposes at least a part of the bonding pad; 
 depositing a conductive layer in the opening, wherein a height difference exists between a top surface of the conductive layer and a top surface of the adjacent mask layer, and the top surface of the conductive layer is lower than the top surface of the adjacent mask layer; 
 forming a cap layer on the conductive layer; and 
 removing the patterned mask layer; 
 wherein the cap layer forming step allows a contacting area between the cap layer and the conductive layer to be substantially equal to the top surface area of the conductive layer; 
 wherein forming the cap layer comprises a reflowing step; 
 wherein the removing step can be achieved concomitantly with the reflowing step under an elevated temperature treatment.